German patent document DE 196 05 999 A1 describes the formation of a contact with a flat antenna conductor structure which can be provided, for example, on a window pane of an automotive vehicle. Below a part of the body of the vehicle a signal processing unit, including for example an antenna amplifier, can be mounted by suitable fastener means. The housing of this unit has a support in the form of an outrigger or cantilever arm, at the end of which a contacting device is provided. This contacting device is connected with the signal processing unit by conductors which are disposed in or on the rigid support. The contacting means effects a contact with contact pads or surfaces of the antenna conductor structure provided on the vehicle window pane.
The rigid carrier allows the bridging of a fixed distance between the antenna conductors and the signal processing unit. Because of the rigid nature of the cantilever arm, tolerances have to be met for the positioning of the signal processing unit with respect to the antenna conductor structure. A further drawback of this construction is that the entire signal processing unit with the carrier and the contacting portion of the device mounted on the carrier must be replaced when any part thereof can be damaged, e.g. in the case of a crash. This involves comparatively high cost since the signal processing unit in most cases is integrated into the vehicle body between the vehicle roof and the ceiling structure of the passenger compartment and thus is not readily accessible.
A further drawback is that the rigid geometry of the support and the parts to which it is connected must always be matched to a particular type of vehicle since every vehicle type has its own configuration of the vehicle body. The result of the need to match a particular construction of the processing unit, the cantilever arm and the contact assembly at the end of it to a particular body structure also means that different tools are required for producing the carriers and bodies for each type of vehicle. The result is the need for a large number of tools.
As a general matter, this earlier system has disadvantages with respect to tooling, with respect to the number of different units required for different vehicle types, the manner in which the units are mounted in the vehicle and in the susceptibility of the system to damage.